One of the great mysteries about antimatter has now been revealed.
Antimatter is a substance that is opposite to matter - which is what stars and planets are made from. During the Big Bang, both matter and antimatter were created in equal amounts and this formed our universe.
However, although we see matter everywhere, its opposite is harder to find.
The latest study, which has been published Nature, found that antimatter falls down under gravity - which is what scientists expected. Antimatter is made of particles possessing the opposite electric charge as ordinary particles.
“Right now, we don’t have an explanation about where all the antimatter in the universe is. To find a solution for this conundrum, what we do is test the elements of the physics of antimatter to see if we can find an inconsistency,” study co-author Robert Thompson from the University of Calgary in Canada said.
The study assessed the gravitational characteristics of antihydrogen – the simplest atom in antimatter that mirrors hydrogen. When matter is the gravitational characteristics of antihydrogen – the simplest atom in antimatter that mirrors hydrogen.
But in the study, this value for antihydrogen – accounting for errors in the experiment – “is consistent with a downward gravitational acceleration of 1g” or about“32 feet per second per second”.
The researchers used the new ALPHA-g apparatus in operation at CERN – Europe’s largest physics laboratory.
Physicists created antimatter and trapped the neutral antihydrogen atoms in a magnetic bottle, making the environment as cold as possible.
Then it was released within the vertical apparatus to witness and measure its gravitational behaviour under free-fall and precise measurements of the antihydrogen's physical attributes were made, including of its charge and colour spectrum.
“Here we show that antihydrogen atoms, released from magnetic confinement in the ALPHA-g apparatus, behave in a way consistent with gravitational attraction to the Earth,” scientists wrote in the study.
Researchers have also ruled out “repulsive ‘antigravity’” in this case – findings that can help better understand the lack of antimatter observed in the universe.
“We know there’s a problem somewhere in quantum mechanics and gravity. We just don’t know what it is. There has been a lot of speculation on what happens if you drop antimatter, though it’s never been tested before now because it’s so hard to produce and gravity is very weak,” Timothy Friesen, another author of the study, said.